Improvement in mold-board blanks



UNITED STATES PATENT QFFICEQ \VILLIAM MEDD WVATSON, OF TONICA, ILLINOIS.

IMPROVEMENT IN MOLD-BOARD BLANKS.

Specification forming part of Letters Patent No. 33,672, dated November 5, 1861.

T0 on whom it may concern:

Be it known that 1, WILLIAM MEDD WAT- soN, formerly named WILLIAM WATSON, of Tonica, in the county of La Salle and State of Illinois, have invented a new and useful manufacture, being an Improved Mold-Board Blank or Skelp for Plows, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings, which make part of this specification, and in which Figure 1 represents four views in perspective of four finished skelps, the skelp A being fiat, the skelp 15 having a curvature in the direction of its length, the skelp 0 having one curvature in the direction of its length and a second transversely across the first, and the skelp D having a curvature diagonally acrossit. Fig. 2 represents in plan and section a sheetof metal rolled into the proper form preparatory to being divided into skelps or sections by shearing it crosswise at the diagonal lines a. Fig. represents a pair of rolls adapted to finishing a sheet or plate flat on one side and having a ridge on the other, as shown in Fig. 2. Fig. 4 represents the cross-section of three rolls for curving a sheet of skelp-plate preparatory to being divided into skelps. Fig. 5 represents in elevation a pair of rolls for giving to the sheet a transverse curvature, while a third roller of the proper form, arranged as shown in Fig. 4, would give the longitudinal curvature.

The means aforesaid for shapingthe skelpsheet are merely suggested as one of the many modes in which the manufacture may, by means well known to those skilled in rolling iron, be produced; but these special means form no part of the invention herein claimed.

In the use of the plow it is found thata narrow strip of that part of the mold-board next to the landside wears away much more rapidly than the rest, and when the mold-board is made of sheet iron or steel of uniform thickness the plow becomes disabled by the wearing out of the front edge of the mold-board next the landside while the rest of the moldboard remains nearly as good as new.

Mold-boards when made of sheet iron or steel are usually formed by rolling a sheet of metal of the proper width for a mold-board and long enough to be divided into several mold-boards by cutting it diagonally across, as shown in Fig. 2 of the drawings, each division 11 being a parallelogram in form, except the two triangular end pieces 0, which are too small for mold-boards, and are laid aside as scrap or waste or for the purpose of making plow-points.

The parallelograms Z) I call mold-board skelps, and if used fiat and in the form in which they are cut the subsequent finishing to complete the mold-board is very simple, as from the form of the bevel at the thick edge little more is required than to drill the holes for the bolts or rivets to unite it to the other parts of the plow, and to polish its front side, and to arm its lower side with a steel edge, which may be secured by bolts, rivets, or welding.

One object of my invention is to produce a mold-board by rolling the metal, which is a cheaper process than forging, that will not be liable to wear out on the edge next the landside sooner than at other points, and this I effect by making the skelp proportionately thicker at and near the landside edge and of the proper shape, so that it will not wear through at and near that edge before it is worn through in the middle and at the opposite side, and at the samat time will require little or no forging to finish this thickened end. These ends are best attained by rolling the skelp sheet with a section of varying thickness, as shown in the drawings, the margin which is to form the landside of the skelp being the thickest. This thickness should be greater for plows designed for a strong soil having a free admixture of sharp sand than for alighteror more pulverulent soil. In general the landside margin should be double the thickness of the middle of the skelp; but for special soils the margin might with advantage be made proportionately thicker or thinner. The sheet may be thickened at and near one edge only, leaving the rest all of a thickness, or it maybe made gradually thinner from the thickened margin to the opposite side, as may be preferred. The sheet should also have its thickened edge beveled, so as to make it parallel to the landside of the plow, the angle of the bevel to the side of the skelp corresponding as nearly as may be to the angle at which it is intended to set the mold-board with redivided by oblique transverse cuts.

spect to the landside. The sheet being thus shaped, it may then be curved transversely or longitudinally, or both, if a fiat mold-board is not preferred, and then it is ready to be divided into skelps. This may be done by rolling or vibrating shears, the sheet being After the skelps are thus cut from the sheet they may be trimmed by shearing or otherwise, into any other shape that may be desired; but the skelps as first cut will approximate very nearly the shape of mold-board most generally preferred.

The surface of the skelp may be smoothed and condensed, so as to give it a planished surface by cold-rolling, and this I prefer, as a planished surface of this kind has less adhesion to the soil and therefore is less liable to clog than a surface polished by grinding.

As a new manufacture,the mold-board skel having a thickened margin, substantially as described.

In testimony whereof I have hereunto subscribed my name.

IVILLIAH MEDD WATSON.

Witnesses:

O. DRYER, J B. DAKIN. 

